This invention relates to rotating and indexing mechanisms applicable to a number of applications that require a mechanism to rotate one component, such as a table, relative to another component, such as a shaft, through a number of equally spaced divisions or stations.
A number of indexing mechanisms exist to simplify and speed up manufacturing processes such as to support and rotate a product for drilling, tapping, and the like.
However, existing indexing mechanisms have a number of drawbacks that make them unsuitable for many applications. For example:
(1) Most indexing mechanisms rely on a rotating input shaft which generally holds a cam to index a table or section that generally supports cam followers. This is a difficult operation if the input shaft is some distance from the operating position or is subsea. Also, electrical motors and their cables are undesirable subsea.
(2) Electrical and hydraulic motors are not capable of rotating an input shaft the small amount required to cause indexing of just one or two stations but are generally for continuous motion, that is, continuously indexing. Additionally, one can never guarantee the exact position of the selectro.
(3) They do not provide high-positioning accuracy at each station, and
(4) They are generally large and bulky, usually comprising three parts, an index box, a reducer, and a drive motor.